The present invention relates to cleaning or unclogging the openings of a photoresist developer dispenser nozzle. The present invention is particularly applicable in improving the efficiency of photolithographic techniques employing positive working photoresist materials.
Conventional practices during various phases in the manufacture of semiconductor devices involve the use of photolithographic techniques. For example, fine patterns and openings are typically formed by photolithographic techniques wherein a photoresist material, such as a positive working photoresist material, is deposited, imagewise exposed, and developed to form a pattern or opening. Etching is then conducted through the opening or pattern to form a corresponding opening or pattern in the underlying layer. Typically, development of the exposed photoresist material is conducted by passing a liquid developer solution or dispersion, suitably selected for the particular photoresist material, through a photoresist developer dispenser nozzle which comprises an inlet and an outlet having a plurality of very fine openings. One such type of spray nozzle is known as an E2 nozzle and is commercially available in combination with a TEL developer system marketed by TEA of Austin, Tex., and manufactured by TEL of Tokyo, Japan.
A problem which typically occurs during photolithographic processing in the semiconductor industry, particularly when developing a positive working photoresist, is frequent clogging of the fine openings of the photoresist developer dispenser nozzle, presumably from developer residue. Such a developer dispenser nozzle clogging problem becomes particularly acute as photolithographic techniques strive to satisfy the ever-increasing demands for miniaturization associated with ultra-large scale integration with increasingly smaller feature sizes.
A conventional approach to the clogging problem associated with dispenser spray nozzles comprises manually removing the nozzle from the developer apparatus and soaking the nozzle in a solution of the type recommended by the developer apparatus manufacturer, such as a solution of isopropyl alcohol and water. This conventional approach to the developer dispenser nozzle clogging problem has not been particularly effective, in that the developer residue which clogs the fine openings is extremely difficult to remove completely. In addition, the conventional manual approach to the developer dispenser nozzle clogging problem is extremely time consuming, normally requiring about two hours, thereby significantly decreasing production throughput. Another disadvantage attendant upon the conventional remedy of manually removing the nozzle from the developer apparatus for cleaning is the necessity to replace the nozzle in a precise position for continued operation in manufacturing integrated circuits.
There exists a need for an apparatus for efficiently cleaning or unclogging a photoresist developer dispenser nozzle. There also exists a need for a rapid, cost-efficient and effective method for cleaning or unclogging the openings of a photoresist developer dispenser nozzle.
An object of the present invention is an apparatus for unclogging the openings of a photoresist developer dispenser nozzle.
Another object of the present invention is a modified photoresist developer apparatus comprising a cleaning system for efficiently unclogging the photoresist developer dispenser nozzle.
A further object of the present invention is a method for efficiently unclogging the openings of a photoresist developer dispenser nozzle.
According to the present invention, the foregoing and other objects are achieved in part by an apparatus comprising: a photoresist developer dispenser nozzle having an inlet and an outlet comprising a plurality of openings; and a pressure cleaning system releasibly connected to the nozzle inlet for unclogging one or more of the openings.
Another aspect of the present invention is an apparatus comprising: a photoresist applicator for depositing a fluid for developing a positive working photoresist; a developer applicator for depositing a fluid for developing a positive working photoresist through a developer dispenser nozzle having an inlet and an outlet comprising a plurality of openings; and a pressure cleaning system releasibly connected to the nozzle inlet for unclogging one or more of the openings.
Another aspect of the present invention is a method of unclogging a developer dispenser nozzle having an inlet and an outlet comprising a plurality of openings, which method comprises flowing a gas under pressure into the inlet through the outlet to unclog at least one of the openings.
A further object of the present invention is a method of unclogging a developer dispenser nozzle having an inlet and an outlet comprising a plurality of openings, which method comprises: connecting a first end of a first gas line to an opening of a container filled with a solution of water and an alcohol; releasibly connecting a second end of the first gas line to the dispenser nozzle inlet; connecting a first end of a second gas line to the container opening; releasibly connecting a second end of the second gas line to a source of pressurized gas; flowing pressurized gas through the second gas line into the container; and flowing the solution under pressure of the gas into the inlet through the developer dispenser outlet to unclog at least one of the openings.
Additional objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.